Tone arm for phonographs



May

R'. RODRIGUEZ TONE ARM FOR PHNoGRAPHs Filed March 2'3', 1921 l NVENTOR Patented May 27, 1924i.,

UN ETE S RAMONl aolnarennz, or NEW YORK, N. Y.

TONE ARM ron rHoNOsaAr-Hs Application led March 23, 1921. Serial No. 454,641.

To @ZZ whom. t may concern:

Be it known that I, RAMON RODRIGUEZ, a subject of the King of Spain, and a resident of the borough of Manhattan, city, county, 'and State of New York, have invented certain new and useful Improvements in Tone Arms for Phonographs, of which the following is a specification.

My invention relates to phonographs and more particularly to 'the tone arms thereof and has for its object to provide a novel tone arm construction whereby the efficiency of the phonograph as a reproducing instrument is materially improved. Other more specific objects of my invention will appear from the description hereinafter and the features of novelty will be pointed out in the appended claim.

In the accompanying drawings which show an example of my invention Without defining its limits, Figure 1 is a side eleva-- tion of the tO-ne arm; Fig. 2 is a sectional view on the line 2-2 of Fig. 1; Fig. 3 is a sectional view on the line 3 3 of Fig. 1; IFig. 4 is a fragmentary, inverted plan view; and Fig. 5 is a detail view of a stop included in the construction.

In the illustrated example, the tone arm comprises a tubular conduit 10 of generally tapering form and preferably formed with a plurality of sections a, b and c which progressively decrease in diameter toward the free end of said conduit 10. The latter is provided at its free end with a suitable coupling 11 adapted for connection with the customary reproducer cl which may be of any well known type. At its opposite or inner end, the conduit is bent transversely to the major axis thereof along a relatively wide curve which terminates in an end member 12, preferably of elongated or more or less oval shape although this is not absolutely essential. The end member 12 fits within a carrying member 13 which preferably corresponds in form to* tubular eXtension 18 forming an integral part of or connected. with a plate 19, preferably circular in form, and whereby the tone arm is secured in position Iinthe phonograph in communicationv with the customary sound conduit which may be of any well known type -and arrangement: 'A cross-bar 2O extends diametrically across the `tubular extension 18 and accommodates an adjustable bearing-screw 21, located in registry with the aXis of said tubular eX- tension 18 and provided at its upper end with a recess 22 arranged to receive and bear against a bearing in the form of a ball-bearing 23. A similar cross-bar 24 eX- tends diametrically'across the neck 15 and is provided at a pointin registery with the axis of said neck with a recess 25 for the accommodation of the ball-bearing 23 previously mentioned. It will be understood that the screw 21 is adjusted in the crossbar 2O in a manner to support the carrying member 13 out of contact with the tubular extension 18; in other words, the carrying member 13 and with it the tone arm is rotatably supported upon the ball-bearing 23 to swing in a horizontal plane with a minimum of friction, the ring 16 serving to prevent the carrying member from being unintentionally or otherwise lifted out `of the tubular extension 18. A stop 26, preferably in the form of anv adjustable screw extends into the carrying member 13 and by engagement with the end member 12, serves to arrest the pivotal movement of the tone army in one direction; that is, in a direction toward the record-.carrying table which forms part of present day phonographs. The stop 26 may extend outwardly beyond the carrying member 13 and in cO-operation with stops 27 spaced from each other upon the plate 19 may serve to arrest the swinging movements of the tone arm in a horizontal plane. The same result may be obtained by providing an interior stop 28 which depends from the cross-bar 24 and is arranged to engage the cross-bar 20 to limit the swinging movements of the tone arm.

The arrangement described provides a construction in which the tone arm is balanoedpto secure the most eicient playing results and at the same time is mounted in a manner to freely move in planes parallel with the plane of the record or, specifically, in horizontal planes, with a minimum of friction. This is due to the Ifact that the tone arin swings in horizontal planes on a single point-bearing represented in the illustrated example, by the ball-bearing 2l, as clearly shown in the drawings.

rlhe improved tone arm is simple in construction. and therefore economical to produce and at the same time is extremely efficient in operation. By adjusting the stop 26, the tone arm may be adjusted to cause vthe reproducer or, more specifically, the needle thereof, to engage the record in a `manner to produce the mostfavorable results in the reproduction of the record in question and to avoid undue pressure upon said record. At the same time the arrangement provides an unimpeded passage for the sound waves set up by the operation of 'the sound-box diaphragm under 'the action of the needle upon the record so that the reproduction is free from disturbing' and foreign noises and corresponds intimately to the original from which the record is made.

Various changes in the specific form shown and described may be made within the scope of the cla-ini with-out departing from the spirit of my invention.

l claim:

ln a phonograph, a stationary tubular supporting` fixture having .at the upper end thereof an inwardly turned annular flange, a carrying member having a reduced bearing neck extending into said tubular supporting fixture, a tone arm secured to said carrying member, a nut secured to said bearing neck below said annular fiange to prevent outvvard removal of said carryingl member and tone arm from said supporting` fixture and means to support said carryingmember upon said supporting fixture for free rotation about a vertical axis, said means comprising a cross bar extending diainetrically across the interior of said supporting fixture, a bearing screw having` a reduced cylindrical extension carried by said cross bar, a cross bar extending diametrivcally across said bearing neck and provided with a recessed bearing` in which said bearing screw is adapted to be engaged to hold said bearing neck concentrically of said tubular supporting fixture.

In testimony whereof I have hereunto set my hand.

RAMON RUDRlG-UEZ. 

